Social influence matters: We follow pandemic guidelines most when our close circle does

Why do we adopt new rules, such as social distancing? Although human sciences research stresses the key role of social influence in behaviour change, most COVID-19 campaigns emphasize the disease’s medical threat. In a global data set (n = 6,675), we investigated how social influences predict people’s adherence to distancing rules during the pandemic. Bayesian regression analyses controlling for stringency of local measures showed that people distanced most when they thought their close social circle did. Such social influence mattered more than people thinking distancing was the right thing to do. People’s adherence also aligned with their fellow citizens, but only if they felt deeply bonded with their country. Self-vulnerability to the disease predicted distancing more for people with larger social circles. Collective efficacy and collectivism also significantly predicted distancing. To achieve behavioural change during crises, policymakers must emphasize shared values and harness the social influence of close friends and family.     

A machine learning approach to infant distress calls and maternal behaviour of wild chimpanzees

Animal Cognition - Distress calls are an acoustically variable group of vocalizations ubiquitous in mammals and other animals. Their presumed function is to recruit help, but there has been much...     

Directedness and engagement in chimpanzee vocal ontogeny

Directedness and engagement during pre-verbal vocal communication play a major role in language development. What was their role in the evolution of language? This question invites us to examine these behaviours in chimpanzee vocal ontogeny. We collected observational data on infant (N = 15) and juvenile (N = 13) chimpanzees at Chimfunshi Wildlife Orphanage, Zambia. We examined the impact of age and vocalization type (grunts, whimpers, laughs and screams) on directed cues (gaze directedness and face directedness) and engagement (mutual face directedness) during vocal communication. We also assessed the impact of directed cues and engagement on social interactions by coding the behaviour of social partners before, during and after a vocalisation, and examining whether they contingently changed their behaviour in response to the vocalisation if it was directed or if engagement occurred. We found that face directed vocalisations showed a general increase during ontogeny and we observed call-type dependent effects of age for mutual face directedness. Only face directed vocalisations were significantly predictive of behavioural responses in social partners. We conclude that like young humans, young chimpanzees routinely exhibit directed behaviours and engagement during vocal communication. This social competency improves during ontogeny and benefits individuals by increasing the chances of eliciting behavioural responses from social partners. Directedness and engagement likely provide a foundation for language phylogenetically, as well as ontogenetically.

Research Highlights

• We show that directedness and engagement routinely occur during early chimpanzee vocalisations.
• Directedness increases throughout chimpanzee vocal ontogeny, similar to human infants.
• Directedness enhances social partner responsiveness, demonstrating a direct benefit to this style of communication.
• Directedness and engagement could provide a route towards language phylogenetically as well as ontogenetically.